import java.util.Scanner;

public class Task {
    /********* Begin *********/
    public static void main(String[] args) throws MyException{
        Scanner sc = new Scanner(System.in);
        String username = sc.next();
        int length = username.length();
        if(length<3){

            throw new MyException("用户名小于三位");
        }
        //判


    }
}

class MyException extends Throwable{
    MyException(String Message){
        super(Message);
    }
}